U.S. President Barack
Obama
condemned the violence in Ukraine, warning the government on Wednesday that "there will be consequences if people step over the line."

Mr. Obama said the U.S. is in contact with European leaders about a way forward.

"We hold the Ukrainian government primarily responsible," Mr. Obama said upon arriving in Mexico for a three-way summit with Canadian and Mexican leaders. "There is still the possibility of a peaceful transition."

Kiev was bracing itself for further violence after overnight clashes left at least 25 people dead, according to the Ukraine government. Despite calls for the violence to stop James Marson says it is difficult to see either the government or protesters stepping down. Photo: Getty Images

The Obama administration also announced Wednesday it would ban visas for 20 Ukrainian officials involved in the violence of recent days and is considering sanctions if the situation does not improve.

A senior State Department official said the individuals were officials in the "chain of command" that the U.S. considers responsible for the violence Tuesday. The official said the U.S. is legally prohibited from releasing the names of the individuals.

"Were they to apply for visas they would be denied," the official said.

The additional sanctions against Ukrainian officials, would likely be pursued in concert with European allies, after the deadly unrest in the country's capital, saying the threat of penalties may push the government in Kiev to halt the violence.

"All of us are deeply disturbed," Secretary of State
John Kerry
said during a brief appearance in Paris with his French counterpart. "We are talking about the possibility of sanctions or other steps with our friends in Europe and elsewhere in order to try to create the environment for compromise."

Mr. Kerry and other U.S. officials didn't detail what those sanctions might entail, but the administration in the past has held out the threat of individual sanctions, typically steps that freeze assets and limit travel.

Why are people protesting in Ukraine? Why has the conflict turned deadly? What are the geopolitics of the conflict? WSJ's Jason Bellini has #TheShortAnswer.

The U.S. threat comes after violent clashes in Kiev this week claimed the lives of at least 25 people and as the Obama administration and its European counterparts try bring the situation under control.

Ukrainian President
Viktor Yanukovych
has blamed opposition leaders for the violence, while opposition leaders said the government was responsible.

Ben Rhodes,
a deputy National Security Adviser to Mr. Obama, said the administration hopes the threat of sanctions will quell some of the violence. "We have made it clear we would consider taking action against individuals who are responsible for acts of violence within Ukraine," he said while traveling with Mr. Obama to Mexico. Mr. Obama is headed to Mexico, among other reasons, to discuss trade.

Renewed violence between protesters and police turned deadly in Kiev. The European Union moved closer to placing sanctions on Ukraine, as violence escalated. WSJ's Laurence Norman reports on the News Hub. Photo: AP.

He is expected to publicly address the situation in Ukraine on Wednesday evening.

Mr. Rhodes said Ukraine could avoid sanctions by talking with the opposition, releasing prisoners and ending the violence.

The Obama administration has for weeks urged an end to the violence. Vice President
Joe Biden
called Mr. Yanukovych on Tuesday and urged him to pull back government forces and exercise maximum restraint. According to a summary of the call released by the White House, Mr. Biden said the U.S. condemns violence by either side, but Ukraine's "government bears special responsibility to de-escalate the situation."